Regulatory - Additional Information (Detail) - USD ($)					1 Months Ended			3 Months Ended
	Aug. 06, 2021	Nov. 19, 2020	Aug. 03, 2020	Jun. 09, 2020	Jan. 31, 2024	Jan. 31, 2023	Jan. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Public Utilities General Disclosures [Line Items]
Accumulated depreciation								$ 3,663,000,000	$ 3,601,000,000
Additional cost recovery from settlement agreement							$ 169,000,000
PGS and OPC [Member]
Public Utilities General Disclosures [Line Items]
Increase in revenue		$ 34,000,000
Allowed equity in the capital structure		54.70%
Accumulated depreciation		$ 34,000,000						34,000,000
Increase in annual base rate		58,000,000
PGS and OPC [Member] | Cast Iron and Bare Steel Replacement Rider [Member]
Public Utilities General Disclosures [Line Items]
Increase in revenue		$ 24,000,000
PGS [Member]
Public Utilities General Disclosures [Line Items]
Accumulated depreciation reversed amount								$ 5,000,000
Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Settlement agreement, approval date	Aug. 06, 2021
Base rate adjustment amount	$ 123,000,000
Increase in revenue	$ 191,000,000
Settlement agreement number of subsequent years adjustments	2 years
Allowed equity in the capital structure	54.00%
Basis point increase applicable	25.00%
Additional attainable revenue under settlement agreement	$ 10,000,000
Changes in base rate under agreement	$ 0
Impact of tax reform through reduction in base revenue days	180 days
Settlement Agreement [Member] | Scenario Forecast [Member]
Public Utilities General Disclosures [Line Items]
Settlement agreement adjustment amount					$ 21,000,000	$ 90,000,000
Settlement Agreement [Member] | US Treasury Bond [Member]
Public Utilities General Disclosures [Line Items]
Calculating period	30 years
Determining period	6 months
Minimum [Member] | PGS and OPC [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE		8.90%
Base rate agreement frozen period		Jan. 01, 2021
Minimum [Member] | Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE	9.00%
Base rate agreement frozen period	Jan. 01, 2022
Minimum [Member] | Settlement Agreement [Member] | US Treasury Bond [Member]
Public Utilities General Disclosures [Line Items]
ROE revenue basis point on yield rate	0.50%
Maximum [Member] | PGS and OPC [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE		11.00%
Base rate agreement frozen period		Dec. 31, 2023
Maximum [Member] | Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE	11.00%
Base rate agreement frozen period	Dec. 31, 2024
Mid Point [Member] | PGS and OPC [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE		9.90%
Mid Point [Member] | Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Percentage of ROE	9.95%
Retiring Assets [Member] | Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Cost recovery from settlement agreement	$ 68,000,000
Retiring Coal Generation Units and Meter Assets [Member] | Settlement Agreement [Member]
Public Utilities General Disclosures [Line Items]
Settlement agreement cost recovery period	15 years
Big Bend Modernization Project [Member]
Public Utilities General Disclosures [Line Items]
Settlement agreement recovery description								Tampa Electric’s Settlement Agreement provides recovery for the Big Bend modernization project in two phases. The first phase is a revenue increase to cover the costs of the assets in service during 2022, among other items. The remainder of the project costs will be recovered as part of the 2023 subsequent year adjustment.
Big Bend Coal Generation Assets [Member]
Public Utilities General Disclosures [Line Items]
Settlement agreement cost recovery period								15 years
Storm Protection Plan [Member]
Public Utilities General Disclosures [Line Items]
Cost recovery from settlement agreement			$ 39,000,000
Reduction in annual base rates				$ 15,000,000